Audiphone-transmitter.



C. E. WILLIAMS.

AUDIPHONE TRANSMITTER.

APPLIoATIoli FILED Amm. 1907.

Patented Feb.2, 1909.

Zark/.5E I :1/9, ,by /lzmmr CHARLES E. WILLIAMS, OF NATICK, MASSACHUSETTS.

' AUDIPHONE-TBANSMITTEB.'

Bpedcation o! Lettera Patent.

Patented Feb. 2, 1909.

Appunti ma Ama s, i901. imm No. semis.

To all whom it may concern:

Be it known that I, CHARLES E. WILLIAMS, a citizen of the United States, and resident of Natick, in the county of Middlesex and State of Massachusetts, have' invented an Improvement in Audi ne-Transmitters, of which the following des 'ption, in connection with the accompanying drawings,is aspeciiication, like letters on the drawings representing like parts.

The object of my invention is to secure clear and more pronounced articulation in the transmission of speech, and greater definition in the transmission of other sounds.

In its general elements my transmitter consists o the usual parts, but I have discovered that, by having an open electrode by rov'iding holes clear through the electrede, instead of 'simply providin 'the electrode `with cupshaIfedepeni'nga, or heidi 'the carbon particles or minute spheres, an by providin' an `exceedingly thin barrier 'at the ront en of these holes, sim ly suiiicient to prevent the particles from fa ng out, and by placing the dia hragm at the back of the instrument instea of at the front, and by roviding a reverberatory chamber at the ront of the instrument, my object is attained in a remarkable degree.

Accordingly, my invention resides, not only in providin an instrument with all the above features, ut it resides in each of said features taken individually, as each feature mentioned above contributes to that extent a distinct ste in advance, and, while I prefer to embody a the features of improvement in one instrument, yet advantageous results ma be obtained from each taken separately, or rom part only taken together.

Besides the above more important features, my invention includes certain others, which are set forth in connection with the follo description of my invention in its preferre details, reference bein had to the accompanying drawings for c earness of understanding.

In the drawi in which I have shown the preferred em odiment of my invention, Figure 1 shows the transmitter in edge ele vation Fig. 2 in front elevation, Iii 3 in central vertical section; Bi' 4 an 5 are transverse sectional det of diiferent forms of reverb era'toiy chambers; Figs. e and 7 show respectively in central vertical seo tion and front elevation and rear elevation a different embodiment of my invention, the

latter figure having certain parts omitted to showthe internal construction; Fig. 8 is a view in plan showing the paper disk for retaining the gauze ho derz which is similarly shown in tig. 10; Fig. 9 is an enlarged frag-u mentary view in central vertical section to show more distinctly the construction and operation of the central electrode.

My instrument proper consists essentially of an electrode 1 supported centrally at the back side of a reverberato chamber 2, whose front side 3 constitutes t e wall against which the spoken sound to be transmitted is directed, and a diaphragm 4 supported at the rear side of the electrode 1 for completing, in connection with suitable circuit wires or connections y veyin'g he Wave impulses. The electrode 1 is provided with Suitable circuit closing granules er articles, Apreferabl in the form of small ear on spheres or b stead of having 't ese particles simply in a cavity in the electrode, the latter is provided with perforations 6, as best shown in F` 9, which extend entirely through the car on button which constitutes the electrode 1. At their front ends the holes 6 are closed by an exceedingly light and thin wall 7. I have found gauze-like material, like chiffon, well adapted for this purpose. For convenience I stretch a piece of the chiion or gauze Wall across the front side of the electrode 1 and secure it by any suitable ineens, either pasting it directly to the electrode 1 or clamping it in position by means of a paper disk 8, shown best in Fig. 8, perforated at 9 to correspond With the holes 6, so as not to interfere in any way with the free thin walls 7. As shown in Fig. 9, an insulating plate 10 is interiosed between the electrode 1 and its mi dle support 11, to which it is secured by any suita e means, as a screw 12 properly insulated therefrom, as shown in detail in Fig. 9. The support 11 is herein shown as provided with a plurality of perforations 13 in line with the holes 6 and with openings 14 for permitting still freer movement of the sound waves, and extends outwardly to receive a part l15 of the supporting case in Fig. 3, and a peripheral ortion, to which is secured by any suitab'e means as by screws 16 3, the reverberatory chamber 2.

In 6 the reverberatory chamber is secured by a metal ann 17. The reverberatory chamber may be composed of hard rubthe usual electrical circuit for con- 5, but, in-

ber, metal, or other substance, according to mentb ch -ber,m it larger 'sition of the ce ls would the tone desired. I refer not to make the reverberato cham er integral with the case, as it is esirable to be able to chan e the chamber, 4 and 5 showing d' erent shapes and sizes of reverberatory chambers placed on the instrument. This reverberatory chamber constitutes an additional chamber made of resonant material located at the front of the electrode chamber, openings 13 or 14, or both, extending between said two chambers, so that sound waves may pass from one chamber to the other, or from the reverberatory chamber through openings in the intervening wall 11 into or through the electrode openings or cells 6 to the globular carbons 5 and t e diaphra 4. Practical experience demonstrates t at ear phones have to be made or set to diierent tones and pitches for different persons to enable them to hear. One person can hear better with a high, sh sound, another can hear better at a ow pitc and a rounder or fuller tone. I get this adjustability on the same instruthe reverberatory chamor smaller and of different sha according to the degree or character of t e deafness of the pprson who is to use it. Accordingly, it willy e at once evident that having the reverberatory chambers made removable or adjustable is a at advantage to the dealer, as well as to t e manufacturer. Not onl are the walls of the electrode chamber an the reverberatory charnber of resilient or resonant material to receive the sound waves from without, but, as they are completely closed or air-tight, the vibration fills them with sound waves, which are thereby am lied by this confinement and the materi composing the walls.

y securing the electrode to the wall between the two chambers, I obtain a rigiditv which is of importance in securing stro electrical variations or sharp transmission o the sound waves. y having a few openiitis 13 in said intervening wall, in addition to e openings through the electrode, I obtain a better articulation than with a at number of said openings. By having t e reverberatorv chamber at the front and the open side of the diaphragm at the back, I get a more sensitive diaphragm action, as fewer of the globular carbons 5 may be used. The instrument, when in use on the 'person naturally inclines backwards, and hence, by having the diaphragm at the rear, the carbons naturally rest lightly against the diaphragm, or heap u as shown in Fig. 9 whereas if the diap agm were in front the carbons would be alling away from the diaphragm, and a git-Bester quantity .would therefore necessarily required, or else the cells made at an angle in order to force the carbons forward against the dia hragm, and said angular porevent the instrument from being as sensitive to the sound the chamber, but the fact is that waves as the preferred construction shown.f By having the cells or perforations of the carbon button 1 o en, I obtain a freer movement of the spherical carbons and allow the sound waves to act more freely and directly u on the carbons and upon the center of the diaphragm. This takes place at the precise moment that the ethereal Waves are bein converted into electrical sound waves, an

thereby conduces still further to sharpness and clearness of articulation. The fine wire or cloth gauze 7 permits the free passage of the air or sound waves. Preferably also I admit the sound Waves simultaneously to the o posits or back side of the diaphragm 4, t being accomplished by providing at the back side of the instrument a cover or ro-- tector 18 in the form of a sounding boar secured by any suitable means to the rim 15 of the casing, as by means of a th'readed ange 19, Fig. 3, the electrode chamber being surrounded bv an annular air space 20 opening toward the front by means of openings 21 at intervals through the peripheral portions of the instrument, said openings, however, not connecting in any way whatever with the reverberatory chamber 2, which, as stated, is closed. By this means that portion of the sound waves which strikes against the imperforate Wall 3 sets up ampued waves in chamber and the electrode chamber, while that portion which strikes the rimeter of the instrument enters through t e opengs 21 into the o en air space 20, and upon st ing the soun ing board 18 is defiected against the backside of the diaplhragm 4, cooperating with the waves whic strike against the front side of said dia hr m. I will not undertake to explain t e t eory of operation of this portion of the device, as it is possible that the rear chamber inclosed by the sounding board 18 also acts as a reverberato by employing it much clearer articulation' resu ts.

In Fig. 6 I have shown the sounding board 18 as concave-convex, and secured by screws 22 to the wall of the electrode chamber, a hard rubber ring 23 closing the edges of the instrument between said front side and said sounding board. The projecting ed es 24 of the sounding board catch and are inuenced by a rtion of the sound waves, but the sounding board is inuenced mainly sound waves which pass throu h t e openings 25, 26 in the front part o the instrument, as shown clearl in Fig. 7. A hook 27, or any other suitab e means of suplptprting the instrument may be provided, e circuit wires are shown at 28, 29, one leading from the diaphragm and the other from the central carbon, as usual in this class of instruments.

As already intimated, my invention may have a wide variety of mechanical embodiconfined air space of the reverberatory by the @Midi mena No@ @1r d@ -I .to im .iiaphf ,s ces-f broadly as* my invention the arrangement of tral buttoi tansersely perforate mounted the central carbon and the reverberaty chamber, but also' the placing f the dia-J hragm at the back and front, providing an imperforate front for receiving and trans-f mitting the sound. Also various other features are herein claimed. The sounding board feature is not herein claimed broadly, as it forms the subject matter of a co ending application, in which I have shown ifferent species of the generic invention.

Having described my invention, what II claim as new, and desire to secure by Letters Patent, is:

1. An audiphone transmitter, provided with means for transmitting sound waves4 electrically, and having a closed reverberatelg7 chamber at its front side for receiving an amplifying the sound waves, and for conveying them to said transmitting means.

2. An audiphone transmitter, provided with means for transmitting sound waves electrically, and having a closed reverbera- .tory chamber removably secured at its front side for receiving and amplifying the sound waves, and for conveying them to said transmitting means.-

3. An audiphone transmitter, provided with means for transmitting sound Waves electrically, including a diaphragm at the rear of the instrument and loose granular circuit-closing means ainst the front side of said diaphragm an having an imperforate front side ior receiving the sound Waves and transmitting them to said da# phragm, the interior of the instrument inclosed between said diaphragm and front Wall being air-tight for amplifying the sound waves transmitted.V

4. An audiphone transmitter, having a wave-transmitting diaphragm located at its back, means including a reverberatory charnber at its front for receiving the sound waves and directing them against the front of the diaphragm, and intervening means coperating With said dia hr in converting the sound Waves into e ectrical`waves, including granular circuit-closing means arranged to rest loosely against the front of said diaphragm.

5. An audiphone transmitter, having a Wave-transmitting diaphra m located at its back, means at its front or receiving the sound Waves, and interve means cooperating with said diaphragm 1n converting the sound waves into electrical waves, including a perforated button, granular circuitclosing means contained in said perforated button in position to rest at one end against said diaphragm, and a thin barrier at the opposite end of the button for retaining said granular means while permitting the passage of sound waves.

6. An audiphone transmitter, having a reeridivis'eT a "scent one side' of said diaphragm, granular e ectrodes carried by sai rated button to rest loosely against sai diaphragm at one end of the utton, and a thin prforate wall closing the button at the o posite end for holding said carbons in whl e permitting free 1 e.- of the air.

7. An audiphone transmitter, having a receiving and transmitting diaph-ra ni, a central button transversely perforate mounted endwise a 'scent one side of said dia hragm, granular e ectrodes carried by sai perforated button to rest loosel against said diaphragm at one end of the utton, and a thin perforate wall of gauze closing' the button at the opposite end or holding said carbons in While ermitting free passage of the air.

8. Xn audiphone transmitter, having a receiving and transmitting diaphragm, a central button transversely perforate mounted endwise adacent one side of said diaphragmJ granular e ectrodes carried by said erforated button to rest loosel against sai diaphragm at one end of the utton, and a thin perforate wall of auze and a retaining ring secured against said gaum and perforated to register with said button closing the button at the opposite end for holding said carbone in while permitting free passage of the air.

9. An audiphone transmitter, comprising an electrode chamber and a reverberatory chamber, a diaphragm closing the rear side of the electrode chamber, a rigid wall separating said chambers, and a button secured rigidly to said intervening wall next to said dia hragm, and granular electrodes loosely hel by said button to engage said diaphragm.

10. An audiphone transmitter, comprising an electrode chamber and a reverberatoy chamber, a diaphragm closing the rear si e of the electrode chamber, a wall se aratin said chambers, and a button secured) to sai interve wall next to said dia hragm, and granular e ectrodes loosely heldy said button to engage said diaphragm said wall and button being transversely perforated to hold said granular electrodes, and said Wall having other erforations affording air com munication etween said two chambers.

11. An audiphone transmitter, having transmission mechanism for converting the sound waves into electrical waves, including a diaphragm anlsgnmular electrodes in position to rest loo y against said diaphragm, and means permitting the sound Waves to act directl uponsaide ectrodes at the instant the soun waves are being converted into electrical Waves.

12. An audiphone transmitter, having mechanism for receiving the sound Waves, and transmission mechanism including a diaphragm for converting the sound waves into erfoelectrical waves, said receiving mechanism includ' means for conveying the sound waves directly to the front side of the diaphragm and means for conveying the sound waves directly to the back side of the diaphragm. f

13. An audiphone transmitter, having mechanism for receiving the soundi waves, and transmission mechanism including a diaphragm for converting the sound waves into electrical waves, said receiving mechanism inclu means for conveying the sound waves directly to the front side lof the diaphragm and means for conveying the sound waves directly to the back side of the dia- 15 phragm, the latter means including a sounding board at back of the instrument and an annular air space about the instrument having openings through the front side.

In testimony whereof I have signed my 20 name to this specication, 'in the presence of two subscribing witnesses.

CHARLES E. WILLIAMS.

Witnesses:

M. J..Siai.niNe, Gino. H. MAXWELL. 

